OF DENISON UNIVERSITY 1 27 



There are sixteen vertical rows of lenses in the eyes and the largest 

 row seems to have contained nine lenses, but this can not be determin- 

 ed since the eye seems to be a little injured below. That part of the 

 fixed cheek which lies between the eyes and the dorsal furrow seems 

 strongly arched, behind the eye this cheek is very narrow and then it 

 widens but moderately before meeting the occipital furrow, which 

 curves forward along the side of the head and here, meeting the fur- 

 row defining the posterior part of the eye, bends forward giving great 

 relief to the eye, and running in a much less distinct form along the 

 base of the incurved front of the glabella. The occipital furrow is 

 everywhere very distinct. The postero-lateral outlines of the head are 

 rounded. The thorax consists of eleven segments. The middle lobe 

 is almost as broad as the lateral lobes, on account of the quite sudden 

 lateral deflection of the pleurae at about half their length. The sides 

 of the segments of the middle lobe are more or luss curved forward, 

 and are slightly thickened. The length of the pygidium is ecpial to 

 about two thirds its width. The middle lobe of the pygidium at its 



anterior portion is about two-sevenths as broad as the pygidium ; it 

 tapers quite rapi'dly posteriorly. It is marked by seven transverse 

 rings of which the sixth is very low and the seventh is very indistinct. 

 The i>ointed tips already mentioned are readily noticeable only on the 

 first ring, on the second they are represented by a low granule, on the 

 third this becomes indistinct, on the fourth they disappear. The lat- 

 eral lobes are marked by six ridges of which the sixth is indistinct. 

 The first ridge is quite broad and is marked by a well defined although 

 shallow furrow. On the second ridge this furrow becomes narrowen 

 on the third it is no longer noticed. The furrows defining the middle 

 lobe are distinct and give it a high relief. 



In Prodr. Pal. Victoria, Dec. III. 1876, Prof. McCoy described 

 from the Upper Silurian beds at Yering Ph. fecundus, Batnifide. 

 Since this is the species most closely related to ours we compared our 

 specimens with the Bohemian species with the following results. In 

 the Bohemian species the compression on each side along the anterior 

 of the glabella is not noticed, this part of the glabella being evenly 

 rounded. The anterior lobe of the glabella is characterized by distinct 

 narrow lunate furrows, of the arrangement tyi)ical with this genus. 

 The middle lobe of the pygidium is less tapering posteriorly, and con- 

 tains eight well characterized transverse rings in addition to a small 

 terminal piece. The ridges or anchylosed segments of the lateral lobes 



